SCOTLAND'S pine martens have been garnering some impressive column inches lately.

The handsome creatures – cat-sized mustelids with a chestnut brown coat, creamy yellow or orange chest bib, round ears and a long bushy tail – are most often in the news being lambasted for preying on fellow protected species, the capercaillie.

Clearly, though, the pine marten has employed a top-notch PR company. The kind of juggernaut publicity machine that wayward footballers and fallen starlets utilise to boost their beleaguered image. In short, the pine marten has gone from villain to hero with a new mantle: saviour of the red squirrel.

It is well documented that the Scottish population of red squirrels has been decimated since the introduction of non-native grey squirrels in Victorian times, largely because greys carry the squirrelpox virus, which leaves them unharmed, but is fatal to the reds.

But grey squirrels are on the march. For the first time, they have been found north of Dunkeld in Perthshire and they are also moving north from Angus into Aberdeenshire. In 2021, grey squirrels were recorded in Pitlochry and north of the River North Esk.

READ MORE: Susan Swarbrick: The high street is dying and our shopping habits are killing Scotland’s countryside

The fear is that the central belt population of grey squirrels will join up with the established Aberdeenshire population to pose an even greater threat to red squirrels.

According to research, the presence of pine martens helps control grey squirrel numbers. In north Scotland, red squirrels have co-existed with pine martens since the early 1980s.

Forestry and Land Scotland (FLS) announced last week that it is installing artificial pine marten dens in forests along the east coast of Scotland and the A9 corridor in a bid to halt the advance of grey squirrels.

The Herald: A pine marten stands on a tree stump among grass and heather. Picture: © Forestry and Land ScotlandA pine marten stands on a tree stump among grass and heather. Picture: © Forestry and Land Scotland

The plan is to position around 30 dens along grey squirrel migration routes and use pine martens as what are being dubbed wildlife "bouncers". Gareth Ventress, FLS environment forester, said: "We need to stop grey squirrels in their tracks."

How do pine martens control grey squirrel numbers? The exact process is not fully understood.

One hypothesis is that red squirrels have evolved to be smaller and lighter, so they can use small, fine branches that heavier pine martens can't access, and this increases their chance of escape.

In Scotland, the presence of field voles could also act as a buffer between red squirrels and pine martens by providing a food source for the latter.

READ MORE: Comedian Craig Hill on the magic of visiting Scotland's 'pyramid' 

Nor is this the pine marten's only foray into the headlines this month. A prospective Croatian euro coin featuring a pine marten has been scrapped amid claims it was based on a picture taken by Scottish photographer Iain Leach and used without his permission.

Mr Leach, a retired consultant histopathologist from Newton Stewart in Dumfries and Galloway, took a picture of a Scottish pine marten perched atop a tree branch on June 8, 2005.

He was surprised to discover that a near-identical photograph had won a contest for a €1 coin, to be launched next year when Croatia joins the single currency.

The designer who submitted the entry to the Croatian National Bank has since withdrawn the image and is said to have handed back a prize of almost €10,000 (£8,350).

READ MORE: TV: Five Scottish thrillers and crime novels headed for our screens

Mr Leach, who has had his work published in National Geographic, has said he had no plans to sue and wished Croatia well in choosing a new design.

How did a pine marten end up on a coin in the first place? The country's kuna, which is being replaced by the euro, is the Croatian word for marten, stemming from the use of its pelt as a form of currency in the Middle Ages.